Strange scheduling behavoir in SMP (kernel 2.2.14)

[Antonio Flores Gil]

Hi,

I have a SMP machine with two Pentium III. In order to compare  performance with other machines I began a simple test:

for (i=0;i<MAX_NUMBER;i++)
  for(j=0;j<MAX_NUMBER;j++)
           c=a*b;               /* These variables could be integer or double */


Using kernel 2.2.12 with SMP support this simple program take more time in my machine than in a uniprocessor with K6-2 (the same problem appear in the last stable kernel 2.2.14) Using xosview
application I discovered where the problem was. Instead of staying all the time in the same cpu, the process go from one cpu to other with a big performance lost.

Am I right?. Has been this problem solved in 2.3.x series?

Thanks a lot in advance.


--
Prof. Antonio Flores Gil
Departamento de Ingeniería y Tecnología de Computadores. Facultad de
Informática. Universidad de Murcia
Campus de Espinardo - 30080 Murcia (SPAIN)
Tel.: +34-968-364638    Fax: +34-968-364151
email: aflores en ditec.um.es




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